Effects of Contrast Water Therapy on Physiological and Perceptual Recovery Following High-Intensity Interval Swimming in Collegiate Swimmers

This study examined the effects of contrast water therapy (CWT) on physiological, perceptual, and performance-related recovery in collegiate male swimmers following high-intensity interval training. Fifteen freestyle swimmers (19.3 ± 1.1 years) completed two sessions of five 100 m maximal-effort intervals under two recovery conditions, CWT and passive rest (PAS), in a crossover design. The CWT protocol consisted of 10 alternating immersions in hot (40-41 °C, 60 s) and cold (20-21 °C, 30 s) water. Blood lactate (LA), blood pressure (BP), and subjective fatigue (VAS-FAS) were assessed at multiple time points. Compared with PAS, CWT resulted in significantly lower post-recovery blood LA (7.75 ± 2.08 vs. 10.86 ± 2.86 mmol/L, <i>p</i> = 0.002) and reduced subjective fatigue (6.60 ± 1.30 vs. 7.60 ± 0.91 cm, <i>p</i> = 0.021), whereas no significant differences were observed in BP or 100-m swimming performance. Individual-level analyses revealed heterogeneous responses, with most swimmers demonstrating improved lactate clearance and reduced fatigue following CWT, although performance responses varied among participants. These findings indicate that CWT facilitates physiological and perceptual recovery without producing immediate performance enhancement. CWT may be considered a practical short-term recovery option for competitive swimmers, although its effectiveness likely depends on individual response characteristics. Further research involving larger and more diverse samples is warranted to clarify optimal application parameters and individual recovery profiles.